DETERMINATION OF WAVE ANGLE IN SHALLOW WATER.

Information from a bidirectional electromagnetic current meter and surface-piercing, continuous resistance wave staff is shown to provide good estimates of the angle of wave approach within the surf zone. Spectra of surface elevation fluctuations ( eta ) define limits to the primary frequencies in the incident wave field, which are then used to define the wave-driven components in the onshore (x) and alongshore (y) velocity spectra. Cross spectra between eta and x and y give squared coherence values used to weight the wave contribution to the motion in any frequency band. A weighted orbital vector for each frequency band is calculated. Summation of the individual angle contributions gives a wave angle representative of the energy distribution in the peak of the incident wave spectrum.